1. Field of the Invention
The present invention relates to tractors for use in farming operations and, more particularly, to tractors readily configurable to meet multiple unique operational requirements and to obtain the benefits therefrom.
2. Description of Related Prior Art
Conventional tractors of greater or lesser size have been used by farmers for decades to pull various implements and to perform various conventional farming operations. For the most part, these tractors are capable of performing the various operations required by a farmer but any reconfiguration, to the extent possible, requires relatively expensive implements and equipments available only from the manufacturer of the tractor. More specific inadequacies and limitations of conventional tractors will be summarized below.
The wheel width of conventional tractors is limited to the length of the associated fixed axles and the width of the tractor is fixed which creates burdens during transport of large tractors. The wheel hubs are fastened to a fixed axle and changing wheel centers is both time consuming and labor intensive. The front axle rocks on a center pin only which renders it impossible to raise one or the other front wheels to roll over obstacles or increase the weight on one or the other of the front wheels. The frame length of a tractor is fixed and by increasing the wheel width without lengthening the wheel base, crabbing results and some stability is lost. Because of the lack of uniformity of tractors from different manufacturers, equipment to be suspended beneath the tractor from the frame requires that each such piece of equipment be specifically designed for a particular tractor due to both the configuration of the frame and the often minimal ground clearance. Sometimes it is beneficial to add weight for traction and such weight must be added manually to a conventional tractor which is labor intensive and hard work. As the frame length of a conventional tractor is fixed, it cannot be shortened to obtain a smaller turning radius and thereby permit cultivation closer to the perimeter of a field. Conventional tractors provide traffic lanes of a two row width, which is an unavoidable limitation of the width of the root zone between the compacted traffic lanes. That is, the compacted traffic lanes create root barriers and reduce the yield.
The frames of most conventional tractors are of a monolithic design with cast-iron components attachable only at specific points of attachment. Thus, attachment of toolbars is generally restricted to front or rear fixed points. The power train components are unique to the configuration of the monolithic design and any repair or replacement requires expensive components available primarily only from the manufacturer of the tractor.
Because of limited clearance between the front wheels and the frame of a conventional tractor, the turning radius is limited. With such limitations and the geometry of conventional steering apparatus, the front wheels tend to plow in a turn and a true turning radius for each of the front wheels is not possible. Moreover, as the front wheels turn about a different point, one or both of the rear wheels may tend to plow or skid.
Toolbars are conventionally mounted at the rear of a tractor, which renders it difficult for an operator to visually monitor the toolbar and operation of the attached equipment. For harvesting and packaging purposes, it is beneficial to permit a farm hand to be on a work platform attached to a tractor but conventional tractors do not have such work platforms.
Conventional guidance systems cause a toolbar to shift and reliance is placed on the tractor to stabilize after such shift. This often causes the tractor to drift sideways.
The size of the tires used with conventional tractors generally cannot be changed. Thus, for greater traction, wider tires must be used or dual tires must be used. In the latter case, a much wider area is compacted to the detriment of crop yield. Usually, an auxiliary axle cannot be added to a conventional tractor to increase traction.